Under certain circumstances, it is useful to be able to modify the values of performance metrics, for example to re-initialize counters or
to assign new values to metrics that act as control variables.
pmstore changes the current values for the nominated instances of a single performance metric, as identified by metricname and the list of
instance identifiers following the -i argument. instances must be a single argument, with elements of the list separated by commas and/or
white space. By default all instances of metricname will be updated.
Normally pmstore operates on the default Performance Metrics Name Space (PMNS), however if the -n option is specified an alternative names-
pace is loaded from the file pmnsfile.
Unless directed to another host by the -h option, pmstore will interact with the Performance Metric Collector Daemon (PMCD) on the local
host.
The interpretation of value is dependent on the syntax used in its specification and the underlying data type of metricname, as follows.
1. If the metric has an integer type, then value should be an optional leading hyphen, followed either by decimal digits or ``0x'' and
some hexadecimal digits. ``0X'' is also acceptable in lieu of ``0x''. See strtol(3C) and the related routines.
2. If the metric has a floating point type, then value should be either in the form of an integer described above, or a fixed point num-
ber, or a number in scientific notation. See strtod(3C).
3. If the metric has a string type, then value is interpreted as a literal string of ASCII characters.
4. If the metric has any other type (i.e. PM_TYPE_EVENT or PM_TYPE_AGGREGATE) then no encoding of value from the command line makes
sense, and the values of these metrics cannot be modified with pmstore.
The output reports the old value and the new value for each updated instance of the requested metric.

FILES

$PCP_VAR_DIR/pmns/*
default PMNS specification files

PCP ENVIRONMENT

Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the
file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative configura-
tion file, as described in pcp.conf(5).

Two messages indicate a mismatch between the internal data type for metricname and the value provided.
The value "???" is out of range for the data type (PM_TYPE_...)
The value "???" is incompatible with the data type (PM_TYPE_...)
Performance Co-Pilot PCP PMSTORE(1)